The 1970's Colt black powder series were raw parts bought from Uberti, but finished here in the US.
I've heard two stories about WHO assembled them, one is they were done in the Colt plant, the other has it done by another gun company FOR Colt.
The later black powder guns as sold in the 1990's were Uberti parts assembled and finished by the John Jovino company in New York under license to Colt.
Since these guns are Colt marked, were either produced by Colt or under license from Colt, and had serial numbers that were continuations of the original number series, they are considered to be Colt revolvers.
$450. for a NIB 70's-80's model is an excellent price.
These usually bring prices at least $100. more on the gun auctions, and often more than that.
Pictures would help, but it's unlikely to be a Colt product.
Colt started the 2nd Generation black powder revolvers serial number where they left off in the 1800's, so a standard production would not have a three digit number.
"Usually" Colt Commemorative models will have a serial number with prefixes that have something to do with the Issue, not a straight number.
More information would help, model? caliber? pictures?
The serial number is "666".
This is an ordinary Italian replica as made by Uberti or Armi San Marko.
The serial number would ordinarily indicate it was an earlier replica, but it was not unusual for American importers like Navy Arms, Dixie Gun Works, and EMF to have their own serial numbers stamped.
None of the genuine Colt Second Generation or Colt licensed Signature models had Italian proof marks such as on your pistol.
A picture of the entire pistol would help us to identify what model of Colt this is a replica of.